The top 10 Democrats in the 2020 presidential race are preparing for a showdown this evening, where Joe Biden and Elizabeth Warren will meet for the first time head-to-head in the primary season.The debate comes following a busy day in Washington, where the House Judiciary Committee approved a key resolution as it gears up towards potential impeachment of Donald Trump. The resolution has defined the boundaries of a probe that Democrats hope could lead to said impeachment, and potentially his removal from office. The move allows the committee to designate certain hearings as impeachment hearings, and empower staff to question witnesses for a longer period of time.